Improvement in artificial legs



UNITE STATES arnNr OFFICE.

IMPROVEMENT IN ARTIFICIAL LEGS.

Specification formlng part of Letters Patent No. 37,637, dated Februaryl0, 1863.

To all whom it may concern:

Be it known that 1, DUBOIS D. PARMELEE, of the city, county, and Stateof New York, have invented certain new and useful Improvements inArtificial Limbs; and I do hereby declare that the followin gis a full,clear, and exact description of the same, reference being had to theaccompanying drawings, forming apart of this specification, in which-Figure l represents a sectional side elevation of a leg constructedaccording to my invention. Fig. 2 is a front view of the same. Fig. 3 isa horizontal section of the saine, taken in the plane indicated by theline a x, Fig. l. Fig. 4 is an inverted plan of the same.

Similar letters of reference in the three views indicate correspondingparts.

The first part of this invention relates to the bucket or socket ofartificial legs or arms intended to receive the stump; and it consistsin the fastening of such bucket to the stump by means of atmosphericpressure in such a manner that the straps usually employed for this4purpose can be dispensed with, and at the saine time a perfect tit ofthe bucket is attained.

The invention consists, further, in the peculiar construction of theknee-joint, which. is formed of two cylindrical rollersone being securedto the upper end of the large bone of the leg (tibia) and the other tothe lower end ofthe thigh bone, (femur,) and each provided with aprojecting lip or stopin combination with an elastic band orspring,lan'd with a double concave sector fitting between the twocylindrical rollers and held in place by metalhc clasps, which also formthe bearings for the axes of said rollers, in such a manner that inwalking the cylinders roll over each other, instead of rubbing, as isthe case with other joints, and consequently the friction isconsiderably diminished, and at the same time, by the elastic band, theforward movement of the foot while walking is facilitated and uniformelastic pressure on the knee-pan is effected.

It consists, further, in dividing the toe-piece of'the foot in two ormore distinct parts, each being provided with a separate joint andadjustable spring in such a manner that the toes can adapt themselves tothe inequalities of the ground.

It consists, nally, in the arrangement of curved tails or shanksprojecting from the toes on the under side or sole of the foot, incombination with suitable leatherstraps and springs and adjusting-clasp,in such a manner that the rigidity in the play of the toes can beregulated at pleasure, and that the toes are kept in the proper positionto prevent interference when bringing the foot forward, and when thefoot is brought down on the ground it presents a comparatively large anda yielding base, and enables the person wearing the leg to maintain hisor her ba-lance with little labor.

To enable those skilled in the art to make and use my invention, I Willproceed to describe it with reference to the drawings.

A represents the bucket or socket to receive the stump of the amputatedlimb. The process by which this bucket is formed is some1 what similarto that by which dentistsform plates of hard rubber to conform perfectlyto the roof of the mouth to be held there by atmospheric pressure. Aform or mold of the stump is prepared in wax or plasterof-paris, (if ofplaster-of-paris the inside ofthe mold should be oiled,) or gutta-perchamay be einployed. Into this mold plaster-of-paris or fusible metal iscast, and thereby a perfect fac-simile or form of the natural stump isobtained. Around this form a sheet of indiarubber or gutta-perchacompound prepared for hard vulcanization is tightly wound and made tosmoothly conform to said form. The

whole is then firmly bound with wetted cloths 4 or embedded inplaster-of-paris, and thus prep'aredit is placed in the heater andvulcanized. After the vulcanization is completed the bucket is taken outand polished and mounted, as will be presently described.

Instead of this mode of obtaining the bucket,

the following process may be found practicable A hollow cone ofvulcanite is formed, the inner circumference of which is the measurementof the stump to be fitted. A form or fac simile of the stump is nexttaken, as above described. The hollow cone is heated to 2120 Fahrenheit,or more, if necessary, and forced "lover the form of the stump andallowed to lcool upon it. rlhe form is next broken out.

is embedded in plaster-of-paris, and then the imetal melted out byimmersion in oil or other liquid capable of sustaining the required tem-@perature The -bucket A is provided'with a l small faucet, a, insertedin its under side, and,

1f of plaster, or if of fusible metal, the whole when properly made byeither of the above or any other suitable process, so perfectly does itfit the stump that on opening the faucet and forcing the stump into saidbucket, and closing the faucet again, the pressure of the atmospherewill hold the bucket in its place till air is readmitted through thefaucet. To obviate any inconvenience from insensible perspiration a drysponge, cotton, wool, or small bag of fused chloride of calcium may beplaced at the bottom of the bucket. rIhis bucket is fastened to thatpart representing the thighbone or femur B, when used for a leg aboveknee, or the stump of the arm or leg below knee by a metal ferrule, Z1.From this ferrule three or more metal bands, c, project, which areriveted to the bucket. By this arrangement it is perfectly easy toadjust the length of the limb with mathematical accuracy simply byshifting the ferrule b up or down on the artificial thigh'bone B untilthe bucket has attained the required position.

G is the knee-joint, which is formed of twol cylinders, d e, one beingfastened to the lower end of the artificial thigh-bone B, and the otherto the upper end ofthe artificial large bone of the leg or tibia l).Each of these cylinders is provided with a lip or off-set, d e', andthey rotate on axles dit et, which have their bearings in metallicclasps f. A double concave sector, g, is placed between the cylinders de, being retained in its place by pivots g', passing through the claspsf. The concave sides of this sector, which fit the surfaces of thecylinders d e, form the articial knee-pan and its edges by coming incontact -with the lips or (ff-set d e', confine the motion of the jointwithin the desired limits. An india-rubber band, 7.1 which is stretched("v ever the convex surface of the knee-pan and around the supports BDhas a tendency to straighten the knee-joint, and thereby assists themovement of the foot forward while walking, and at the same time auniform elasticity is obtained by said band over the artificialknee-pan. rlhe cylinder d rolls on the surface of the lower one, e, andthe friction created by the working parts of the joint is reduced to thesmallest possible degree. The heel or ankle-joint E is formed of twopieces, t j, one of which is provided with a semispherical socket andthe other with a corre sponding prominence, as clearly shown in Fig. lof the drawings. This prominence t-s perfectly the socket, and eachofthe two pieces t' j is provided with flanges projecting beyond thesocket and prominence, whereby the movement or play of said parts ineither direction is confined between limits, such as may be desiredbythe constructor. rlhe upper part, t', of the heel-joint is fastened tothe lower end of the articial tibia,

and the lower part, j, of said joint is screwed or otherwise firmlysecured to the foot-piece F, and the two parts t' j are fastenedtogether by an india-rubber tube, 7u, of proper thickness and strengthto attain the effect desired, which is stretched over the same andsecured to each part by tying with cord or in any other desirablemanner. The foot-piece F corresponds to the bones of the instep andheel-hone ofthe natural foot. Its front end, Z, is rounded off and formsthe fulcrum for the piece G. This piece is divided into three (more orless) distinct parts, m m m, one of which corresponds to the large toe,and each of the others to two of the other toes, as clearly shown inFigs. 3 and 4 ofthe drawings. These toe-pieces are held in place bybands n, ofleather or other inelastic but flexible material, fastened bymeans of screws or any other desirable means to the under side of thesame an d of the foot-piece, and by elastic bands 0, of india-rubber orany other suitable material, fastened by any convenient mode to theupper surface and that of the footpiece, as clearly shown in Figs.1,3,and 4r. rllhe inner ends ofthe elasticbands o pass through ametalclasp, ya, so as to admit tightening or loosening,accord ing to therequisite rigidity desired in theplay of the toes. By the action ofthese elastic bands or springs the points of the toes are thrown up soas to prevent interference when bringing 4the foot forward, and theirposition is regulated by the length of the leather'bands n, which bearagainst the stems or tails mit', eX- tending from the toe-pieces m m mbelow the point of the foot-piece F, as shown in Fig. l of the drawings.lf the weight of the body is upon the front of the foot, by the actionofthe tails mt the toe-pieces are turned down and a large base isattained, thereby enabling the person wearing the leg to maintain his orher balance with little labor. By the division of the toes they areenabled to adapt themselves to an unequal surface. The heel H is coveredby an elastic pad, to prevent any jarring in the act of walking. Thecase for this leg or arm may be made of cork, papier-mache, or any othersuitable material, but that form I would recommend would consist of aleather tube cut into the shape ofthe limb, sewed up, and small hoops ofsteel springs placed and fastened on the interior at about three inchesapart to give form to the case, and at the same time preserve itsflexibility. Such a case might be fastened by hooks to the bucket at thetop, and when used for a leg be made to connect at the 'bottom with theleather boot, inclosing the foot.

The principal advantages of my artificial limb are that it can befastened to the stump without the use of straps around the waist orshoulder, and it requires no tedious fitting. With limbs of the ordinaryconstruction the patient is required to sit and wait for repeatedtrials, while the artisan scrapes away the Wood to t the socket, andthis operation is hardly ever attended with perfect success until afterseveral trials of the leg. Furthermore, my knee-joint works with theleast possible friction. It is simple, cheap, durable, and not liable toget out of order, and the toe- A piece of an ordinary leg presents notquite one-half the area for basal support that is attained by thepeculiar arrangement of the toepiece in my leg.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. Fastening the bucket A of an artificial limb to the stump by means ofatmospheric pressure, substantially in the manner specilied.

2. The knee-joint C constructed of two cylinders, d e, clasps f, doubleconcave-sector g, and elastic band h, all arranged and operatingsubstantially in the ina-nner and for the purpose herein shown anddescribed.

3. Dividing the toe-piece G in two or more v distinct parts,substantially as and tor the purp'ose set forth.

4. The arrangement of the stems or tails n mit, projectingfrolnthe underside of the toepieces mm fm, in combination with the bands u, of leatheror other suitabe material, and with the elasticbands 0, afjustable by ametal clasp 19, or its equivalent, ill constructed and operatingsubstantially in the manner and for the purpose described.

DUBOIS D. PARMELEE. Witnesses:

TIMOTHY SHINE, M. S. PARTRIDGE.

